Enanta Pharmaceuticals (ENTA) 10-Q 6 Feb 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Dec. 31, 2014	Jan. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Trading Symbol	ENTA
Entity Registrant Name	ENANTA PHARMACEUTICALS INC
Entity Central Index Key	1177648
Current Fiscal Year End Date	-21
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		18,680,414

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Sep. 30, 2014
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$34,130	$30,699
Short-term marketable securities	69,892	60,065
Accounts receivable	76,626	1,724
Unbilled receivables	1,882	2,770
Deferred tax assets	1,348	11,123
Prepaid expenses and other current assets	1,218	1,594
Total current assets	185,096	107,975
Property and equipment, net	1,922	1,803
Long-term marketable securities	23,568	41,003
Deferred tax assets	4,405	4,198
Restricted cash	436	436
Total assets	215,427	155,415
Current liabilities:
Accounts payable	567	1,874
Accrued expenses	2,403	2,872
Income taxes payable	16,896
Total current liabilities	19,866	4,746
Warrant liability	1,427	1,584
Other long-term liabilities	238	229
Total liabilities	21,714	6,761
Commitments and contingencies (Note 11)
Stockholders' equity:
Common stock; $0.01 par value; 100,000,000 shares authorized at December 31, 2014 and September 30, 2014, respectively; 18,822,045 and 18,803,390 shares issued and 18,613,229 and 18,594,574 shares outstanding at December 31, 2014 and September 30, 2014, respectively	188	188
Additional paid-in capital	224,622	221,580
Treasury stock, at par value; 208,816 shares at December 31, 2014 and September 30, 2014, respectively	-2	-2
Accumulated other comprehensive loss	-92	-100
Accumulated deficit	-31,003	-73,012
Total stockholders' equity	193,713	148,654
Total liabilities and stockholders' equity	215,427	155,415
Series 1 Nonconvertible Preferred Stock [Member]
Current liabilities:
Series 1 nonconvertible preferred stock	$183	$202

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Sep. 30, 2014
Statement of Financial Position [Abstract]
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	18,822,045	18,803,390
Common stock, shares outstanding	18,613,229	18,594,574
Treasury stock, shares	208,816	208,816

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Revenue	$77,498	$893
Operating expenses:
Research and development	4,519	4,263
General and administrative	2,769	2,087
Total operating expenses	7,288	6,350
Income (loss) from operations	70,210	-5,457
Other income (expense):
Interest income	127	109
Interest expense	-2	-5
Change in fair value of warrant liability and Series 1 nonconvertible preferred stock, net	176	-17
Total other income, net	301	87
Net income (loss) before income taxes	70,511	-5,370
Income tax expense	-28,502	0
Net income (loss)	$42,009	($5,370)
Net income (loss) per share:
Basic	$2.26	($0.30)
Diluted	$2.18	($0.30)
Weighted average common shares outstanding:
Basic	18,603,067	17,949,472
Diluted	19,283,223	17,949,472

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Loss) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income (loss)	$42,009	($5,370)
Other comprehensive income loss:
Net unrealized gains on marketable securities, net of tax of $3 and $0	5	34
Total other comprehensive income	5	34
Comprehensive income (loss)	$42,014	($5,336)

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net unrealized gains (losses) on marketable securities, tax	$3	$0

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities
Net income (loss)	$42,009	($5,370)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation and amortization expense	129	75
Non-cash interest expense	2	5
Change in fair value of warrant liability and Series 1 nonconvertible preferred stock	-176	17
Stock-based compensation expense	1,028	359
Gain on sale of marketable securities	-1
Premium on marketable securities	-169	-425
Amortization of premium on marketable securities	471	635
Deferred income taxes	11,487
Income tax benefit from exercise of stock options	-1,919
Changes in operating assets and liabilities:
Accounts receivable	-74,902	529
Unbilled receivables	888	-145
Prepaid expenses and other current assets	409	405
Accounts payable	-1,296	-648
Accrued expenses	-475	-1,317
Income taxes payable	16,896
Deferred revenue		-5
Other long-term liabilities	9	14
Net cash used in operating activities	-5,610	-5,871
Cash flows from investing activities
Purchases of property and equipment	-256	-24
Purchases of marketable securities	-8,153	-10,221
Sales of marketable securities	2,210	3,373
Maturities of marketable securities	13,226	8,221
Net cash provided by investing activities	7,027	1,349
Cash flows from financing activities
Proceeds from exercise of stock options	95	89
Income tax benefit from exercise of stock options	1,919
Net cash provided by financing activities	2,014	89
Net increase (decrease) in cash and cash equivalents	3,431	-4,433
Cash and cash equivalents at beginning of period	30,699	8,859
Cash and cash equivalents at end of period	34,130	4,426
Supplemental disclosure of cash flow information:
Cash paid for income taxes	66
Series 1 Nonconvertible Preferred Stock [Member]
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Change in fair value of warrant liability and Series 1 nonconvertible preferred stock	($176)	$17

Nature_of_the_Business_and_Bas

Nature of the Business and Basis of Presentation	3 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Nature of the Business and Basis of Presentation	1	Nature of the Business and Basis of Presentation
	Enanta Pharmaceuticals, Inc. (the “Company”), incorporated in Delaware in 1995, is a research and development-focused biotechnology company that uses its chemistry-driven approach and drug discovery capabilities to create small molecule drugs for the treatment of viral infections and liver diseases. The Company has programs to develop novel protease, NS5A, cyclophilin and nucleotide polymerase inhibitors targeted against the hepatitis C virus (“HCV”) and also recently announced a new focus area in non-alcoholic steatohepatitis (NASH). Additionally, the Company has programs to discover new chemical entities for the treatment of other diseases.
	The Company is subject to risks common to companies in the biotechnology industry including, but not limited to, the uncertainties of research and development, competition from technological innovations of others, dependence on collaborative arrangements, protection of proprietary technology, dependence on key personnel, compliance with government regulations and the need for financial resources to fund research and development activities. Product candidates currently under development will require significant additional research and development efforts, including extensive preclinical and clinical testing and regulatory approval, prior to commercialization. These efforts require significant amounts of additional capital, adequate personnel infrastructure and extensive compliance reporting capabilities.
	Unaudited Interim Financial Information
	The consolidated balance sheet at September 30, 2014 was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America (“GAAP”). The accompanying unaudited consolidated financial statements as of December 31, 2014 and for the three months ended December 31, 2014 and 2013 have been prepared by the Company, pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. These financial statements should be read in conjunction with the Company’s audited financial statements and the notes thereto for the year ended September 30, 2014 included in the Company’s Annual Report on Form 10-K.
	In the opinion of management, all adjustments, consisting only of normal recurring adjustments necessary for a fair statement of the Company’s financial position as of December 31, 2014 and results of operations for the three months ended December 31, 2014 and 2013 and cash flows for the three months ended December 31, 2014 and 2013 have been made. The results of operations for the three months ended December 31, 2014 are not necessarily indicative of the results of operations that may be expected for the year ending September 30, 2015.
	The accompanying consolidated financial statements have been prepared in conformity with GAAP. All dollar amounts in the consolidated financial statements and in the notes to the consolidated financial statements, except share and per share amounts, are in thousands unless otherwise indicated.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	3 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2	Summary of Significant Accounting Policies
	Use of Estimates
	The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the consolidated financial statements, and the reported amounts of revenues and expenses during the reporting period. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, valuation of warrants, Series 1 nonconvertible preferred stock and stock-based awards; the useful lives of property and equipment; and the accounting for income taxes, including uncertain tax positions. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from the Company’s estimates.
	Revenue Recognition
	The Company’s revenue is generated primarily through collaborative research and license agreements. The terms of these agreements contain multiple deliverables, which may include (i) licenses, (ii) research and development activities, and (iii) participation in joint research and development steering committees. The terms of these agreements may include nonrefundable upfront license fees, payments for research and development activities, payments based upon the achievement of certain milestones, and royalty payments based on product sales derived from the collaboration. In all instances, revenue is recognized only when the price is fixed or determinable, persuasive evidence of an arrangement exists, delivery has occurred or the services have been rendered, collectibility of the resulting receivable is reasonably assured, and the Company has fulfilled its performance obligations under the contract.
	For agreements entered into prior to October 1, 2011, the Company evaluated license agreements with multiple deliverables to determine if the deliverable elements could be recognized separately by considering (i) if the delivered elements (typically the license) had standalone value to the customer, (ii) if the fair value of any undelivered elements (typically the research and development services and the steering committee activities) could be determined based on vendor-specific objective evidence (“VSOE”) or vendor objective evidence (“VOE”), and (iii) if the arrangement included a general right of return relative to the delivered item, the delivery or performance of the undelivered item was considered probable and substantially within the control of the Company. VSOE of fair value was based on the consistent price of a deliverable when the Company regularly sold it on a standalone basis. Alternatively, VOE was based upon third-party objective evidence of fair value. If the delivered elements had value on a standalone basis and the fair value of the undelivered elements could be determined based on VSOE or VOE, revenues of such elements were then accounted for separately as delivered with arrangement consideration allocated to the delivered elements based on the residual value method. If either (i) the delivered elements were considered to not have standalone value or (ii) VSOE or VOE of fair value for any of the undelivered elements could not be determined, the arrangement was accounted for as a single unit of accounting and all payments received were recognized as revenue over the estimated period of performance of the entire arrangement.
	On October 1, 2011, the Company adopted Accounting Standards Update (“ASU”) No. 2009-13, Multiple-Deliverable Revenue Arrangements (“ASU 2009-13”). This guidance, which applies to multiple-element arrangements entered into or materially modified on or after October 1, 2011, amends the criteria for separating and allocating consideration in a multiple-element arrangement by modifying the fair value requirements for revenue recognition and eliminating the use of the residual value method. The selling prices of deliverables under the arrangement may be derived using third-party evidence (“TPE”) or a best estimate of selling price (“BESP”), if VSOE is not available. The objective of BESP is to determine the price at which the Company would transact a sale if the element within the license agreement was sold on a standalone basis. Establishing BESP involves management’s judgment and considers multiple factors, including market conditions and company-specific factors including those factors contemplated in negotiating the agreements as well as internally developed models that include assumptions related to market opportunity, discounted cash flows, estimated development costs, probability of success, and the time needed to commercialize a product candidate pursuant to the license. In validating the Company’s BESP, the Company considers whether changes in key assumptions used to determine the BESP will have a significant effect on the allocation of the arrangement consideration between the multiple deliverables. Deliverables under the arrangement are separate units of accounting if (i) the delivered item has value to the customer on a standalone basis, and (ii) if the arrangement includes a general right of return relative to the delivered item, delivery or performance of the undelivered item is considered probable and substantially within the control of the Company. The arrangement consideration that is fixed or determinable at the inception of the arrangement is allocated to the separate units of accounting based on their relative selling prices. The appropriate revenue recognition model is applied to each element, and revenue is accordingly recognized as each element is delivered. The Company may exercise significant judgment in determining whether a deliverable is a separate unit of accounting. The Company elected to adopt ASU 2009-13 prospectively as of October 1, 2011.
	In determining the separate units of accounting, the Company evaluates whether the license has standalone value to the collaborator based on consideration of the relevant facts and circumstances for each arrangement. Factors considered in this determination include the research and development capabilities of the collaborator and the availability of relevant research expertise in the marketplace. In addition, the Company considers whether or not (i) the collaborator can use the license for its intended purpose without the receipt of the remaining deliverables, (ii) the value of the license is dependent on the undelivered items, and (iii) the collaborator or other vendors can provide the undelivered items.
	Under a collaborative research and license agreement, a steering committee is typically responsible for overseeing the general working relationships, determining the protocols to be followed in the research and development performed, and evaluating the results from the continued development of the product in order to determine the clinical studies to be performed. The Company evaluates whether its participation in joint research and development steering committees is a substantive obligation or whether the services are considered inconsequential or perfunctory. The Company’s participation on a steering committee is considered “participatory” and therefore accounted for as a separate element when the collaborator requires the participation of the Company to ensure all elements of an arrangement are maximized. Steering committee services that are considered participatory are combined with other research services or performance obligations required under an arrangement, if any, in determining the level of effort required in an arrangement and the period over which the Company expects to complete its aggregate performance obligations. Alternatively, the Company’s participation on a steering committee is considered “protective” and therefore not accounted for as a separate element in a case where the Company can exercise or control when to be involved at its own discretion. Factors the Company considers in determining if its participation in a joint steering committee is participating or protective include: (i) which party negotiated or requested the steering committee, (ii) how frequently the steering committee meets, (iii) whether or not there are any penalties or other recourse if the Company does not attend the steering committee meetings, (iv) which party has decision making authority on the steering committee, and (v) whether or not the collaborator has the requisite experience and expertise associated with the research and development of the licensed intellectual property.
	For all periods presented, whenever the Company determines that an element is delivered over a period of time, revenue is recognized using either a proportional performance model or a straight-line model over the period of performance, which is typically the research and development term. Full-time equivalents (“FTEs”) are typically used as the measure of performance. At each reporting period, the Company reassesses its cumulative measure of performance and makes appropriate adjustments, if necessary. The Company recognizes revenue using the proportional performance model whenever the Company can make reasonably reliable estimates of the level of effort required to complete its performance obligations under an arrangement. Revenue recognized under the proportional performance model at each reporting period is determined by multiplying the total expected payments under the contract (excluding royalties and payments contingent upon achievement of milestones) by the ratio of the level of effort incurred to date to the estimated total level of effort required to complete the performance obligations under the arrangement. Revenue is limited to the lesser of the cumulative amount of payments received or the cumulative amount of revenue earned, as determined using the proportional performance model as of each reporting period. Alternatively, if the Company cannot make reasonably reliable estimates of the level of effort required to complete its performance obligations under an arrangement, then revenue under the arrangement is recognized on a straight-line basis over the period expected to complete the Company’s performance obligations. If and when a contingent milestone payment is earned, the additional consideration to be received is allocated to the separate units of accounting in the arrangement based on their relative selling prices at the inception of the arrangement. Revenue is limited to the lesser of the cumulative amount of payments received or the cumulative amount of revenue earned, as determined on a straight-line basis as of the period end date. If the Company cannot reasonably estimate when its performance obligation period ends, then revenue is deferred until the Company can reasonably estimate when the performance obligation period ends.
	Royalty revenue is recognized based on contractual terms when reported sales are reliably measurable and collectibility is reasonably assured, provided that there are no performance obligations then remaining.
	During the three months ended December 31, 2014 and 2013 the Company also generated revenue from a government contract, under which the Company is reimbursed for certain allowable costs for the funded project. Revenue from the government contract is recognized when the related service is performed. The related costs incurred by the Company under the government contract are included in research and development expenses in the statements of operations.
	Amounts received prior to satisfying all revenue recognition criteria are recorded as deferred revenue in the accompanying consolidated balance sheets. Amounts not expected to be recognized as revenue within the next twelve months of the consolidated balance sheet date are classified as long-term deferred revenue.
	In the event that a collaborative research and license agreement is terminated and the Company then has no further performance obligations, the Company recognizes as revenue any amounts that had not previously been recorded as revenue but were classified as deferred revenue at the date of such termination.
	Recently Issued Accounting Pronouncements
	In May, 2014, the Financial Accounting Standards Board (the “FASB”) issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), which supersedes all existing revenue recognition requirements, including most industry-specific guidance. The new standard requires a company to recognize revenue when it transfers goods or services to customers in an amount that reflects the consideration that the company expects to receive for those goods or services. The new standard will be effective for us on October 1, 2017. The Company is currently evaluating the potential impact that Topic 606 may have on its financial position and results of operations.

Fair_Value_of_Financial_Assets

Fair Value of Financial Assets and Liabilities	3 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value of Financial Assets and Liabilities	3	Fair Value of Financial Assets and Liabilities
	The following tables present information about the Company’s financial assets and liabilities that were subject to fair value measurement on a recurring basis as of December 31, 2014 and September 30, 2014 and indicate the fair value hierarchy of the valuation inputs utilized to determine such fair value:
			Fair Value Measurements as of December 31, 2014 Using:
			Level 1			Level 2			Level 3		Total
	Assets:
	Money market fund		$	27,046		$	—		$	—	$	27,046
	Commercial paper			—			5,000			—		5,000
	Corporate bonds			—			87,951			—		87,951
	U.S. Agency bonds			—			5,509			—		5,509
			$	27,046		$	98,460		$	—	$	125,506
	Liabilities:
	Warrant liability		$	—		$	—		$	1,427	$	1,427
	Series 1 nonconvertible preferred stock		$	—		$	—		$	183	$	183
			$	—		$	—		$	1,610	$	1,610
			Fair Value Measurements as of September 30, 2014 Using:
			Level 1			Level 2			Level 3		Total
	Assets:
	Money market fund		$	30,239		$	—		$	—	$	30,239
	Commercial paper			—			7,499			—		7,499
	Corporate bonds			—			88,056			—		88,056
	U.S. Agency bonds			—			5,513			—		5,513
			$	30,239		$	101,068		$	—	$	131,307
	Liabilities:
	Warrant liability		$	—		$	—		$	1,584	$	1,584
	Series 1 nonconvertible preferred stock		$	—		$	—		$	202	$	202
			$	—		$	—		$	1,786	$	1,786
	During the three months ended December 31, 2014 and 2013, there were no transfers between Level 1, Level 2 and Level 3.
	As of December 31, 2014 and September 30, 2014, respectively, the warrant liability was comprised of the values of warrants for the purchase of Series 1 nonconvertible preferred stock measured at fair value. The outstanding Series 1 nonconvertible preferred stock was also measured at fair value. The fair value of both of these instruments was based on significant inputs not observable in the market, which represented a Level 3 measurement within the fair value hierarchy. The Company utilized a probability-weighted valuation model which takes into consideration various outcomes that may require the Company to transfer assets upon exercise. The fair value of warrants to purchase our Series 1 nonconvertible preferred stock was $1,427 and $1,584, at December 31, 2014 and September 30, 2014, respectively. The fair value of Series 1 nonconvertible preferred stock was $183 and $202 as of December 31, 2014 and September 30, 2014, respectively. Changes in the fair value of the warrant liability and Series 1 nonconvertible preferred stock are recognized in the consolidated statements of operations.
	The recurring Level 3 fair value measurements of the Company’s warrant liability and Series 1 nonconvertible preferred stock using probability-weighted discounted cash flow include the following significant unobservable inputs:
			Unobservable Input		Range
					(Weighted
					Average)
	Warrant liability and Series 1 nonconvertible preferred stock		Probabilities of payout		10% - 55%
			Periods in which payout is expected to occur		2016 – 2017
			Discount rate		4.25%
	The following table provides a rollforward of the aggregate fair values of the Company’s warrants for the purchase of Series 1 nonconvertible preferred stock and the outstanding Series 1 nonconvertible preferred stock for which fair value is determined by Level 3 inputs:
			Warrant			Series 1
			liability			nonconvertible
						preferred
						stock
	Balance, September 30, 2014		$	1,584		$	202
	Decrease in fair value			(157	)		(19	)
	Balance, December 31, 2014		$	1,427		$	183

Marketable_Securities

Marketable Securities	3 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	4	Marketable Securities
	As of December 31, 2014 and September 30, 2014, the fair value of available-for-sale marketable securities by type of security was as follows:
			December 31, 2014
			Amortized Cost		Gross Unrealized		Gross Unrealized			Fair Value
					Gains		Losses
	Corporate bonds		$	88,042	$	11	$	(102	)	$	87,951
	U.S. Agency bonds			5,510		—		(1	)		5,509
			$	93,552	$	11	$	(103	)	$	93,460
			September 30, 2014
			Amortized Cost		Gross Unrealized		Gross Unrealized			Fair Value
					Gains		Losses
	Commercial paper		$	7,499	$	—	$	—		$	7,499
	Corporate bonds			88,156		14		(114	)		88,056
	U.S. Agency bonds			5,513		—		—			5,513
			$	101,168	$	14	$	(114	)	$	101,068
	As of December 31, 2014, marketable securities consisted of investments that mature within one year, with the exception of certain corporate bonds, which have maturities within three years and an aggregate fair value of $23,568.
	As of September 30, 2014, marketable securities consisted of investments that mature within one year, with the exception of certain corporate bonds and U.S. Agency bonds, which have maturities within three years and an aggregate fair value of $41,003.

Accrued_Expenses_and_Other_Lon

Accrued Expenses and Other Long-Term Liabilities	3 Months Ended
	Dec. 31, 2014
Payables and Accruals [Abstract]
Accrued Expenses and Other Long-Term Liabilities	5	Accrued Expenses and Other Long-Term Liabilities
	Accrued expenses (current) and other long-term liabilities consisted of the following as of December 31, 2014 and September 30, 2014:
			December 31,		September 30,
			2014		2014
	Accrued expenses:
	Accrued payroll and related expenses		$	584	$	1,275
	Accrued preclinical and clinical expenses			568		493
	Accrued vendor manufacturing			412		116
	Accrued third-party license fees			299		240
	Accrued professional fees			228		436
	Accrued other			312		312
			$	2,403	$	2,872
	Other long-term liabilities:
	Accrued rent expense		$	153	$	153
	Asset retirement obligation			85		76
			$	238	$	229

Collaboration_Agreements

Collaboration Agreements	3 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Collaboration Agreements	6	Collaboration Agreements
	AbbVie Collaboration
	On November 27, 2006, the Company entered into a Collaborative Development and License Agreement (the “AbbVie Agreement”) with Abbott Laboratories to identify, develop and commercialize HCV NS3 and NS3/4A protease inhibitor compounds, including paritaprevir (previously known as ABT-450). The agreement, which was amended in January and December 2009, was assigned by Abbott to AbbVie Inc. on January 1, 2013 in connection with Abbott’s transfer of its research-based pharmaceuticals business to AbbVie.
	Under the terms of the AbbVie Agreement, as amended, AbbVie paid to the Company upfront license payments and FTE reimbursements to fund research activities. The Company is also eligible to receive milestone payments for the successful development by AbbVie of one or more HCV compounds as well as annually tiered royalties per product ranging from the low double digits up to twenty percent, or on a blended basis from the low double digits up to the high teens, on net sales by AbbVie allocated to the collaboration’s protease inhibitors. Under the terms of the agreement, as amended in October 2014, 30% of net sales of a 3-DAA regimen containing paritaprevir will be allocated to paritaprevir, and 45% of net sales of a 2-DAA regimen containing paritaprevir will be allocated to paritaprevir. For ABT-493, 50% of net sales of a 2-DAA regimen containing ABT-493 will be allocated to ABT-493, and for a 3-DAA regimen containing ABT-493, 33 1⁄3% of net sales will be allocated to ABT-493. If there is any active ingredient other than DAA’s in any ABT-493-containing regimen sold by AbbVie, there will be a further adjustment to net sales based on the relative value of the non-DAA ingredient.
	Deliverables under the AbbVie Agreement included a license, research services and participation on a steering committee. The Company concluded that all deliverables under the AbbVie Agreement should be treated as a single unit of accounting. Accordingly, revenue was recognized using the proportional performance model over the period during which the Company performed research services. The Company completed all remaining service obligations under the agreement as of June 2011. All milestone payments received after June 2011 are recognized as revenue when each milestone is achieved by AbbVie.
	Through September 30, 2014, the Company had received upfront license payments, proceeds from a sale of preferred stock, research funding payment, and milestone payments totaling $160,000 from AbbVie.
	During the three months ended December 31, 2014, the Company earned and recognized as revenue a $75,000 milestone amount due from AbbVie as a result of U.S. regulatory approval by the FDA for AbbVie’s first treatment regimen containing a collaboration compound. The Company’s first product, paritaprevir, was approved on December 19, 2014 as part of AbbVie’s new treatment regimen for HCV. The Company has earned royalty revenue from product sales for the first time in the quarter ended December 31, 2014.
	As of December 31, 2014, the Company was eligible to receive additional milestone payments totaling up to $80,000 upon AbbVie’s achievement of commercialization regulatory approval milestones for paritaprevir in selected world markets outside of the U.S. On January 16, 2015 the Company announced that the European Commission granted marketing authorizations for AbbVie’s VIEKIRAX® (ombitasvir/paritaprevir/ritonavir tablets) + EXVIERA® (dasabuvir tablets) with or without ribavirin (RBV) for the treatment of patients with chronic genotype 1 (GT1) hepatitis C virus (HCV) infection and VIEKIRAX with ribavirin for chronic genotype 4 (GT4) HCV infection. The Company is entitled to a $50,000 milestone payment from AbbVie upon commercialization regulatory approval of VIEKIRAX in Europe, which is expected to be received in the quarter ending March 31, 2015.
	The Company is also eligible to receive additional milestone payments totaling up to $80,000 upon AbbVie’s achievement of similar commercialization regulatory approval milestones in the U.S. and other selected world markets for each additional product containing a new protease inhibitor.
	Novartis Collaboration
	On February 16, 2012, the Company entered into a license and collaboration agreement with Novartis (the “Novartis Agreement”) for the development, manufacture and commercialization of its lead development candidate, EDP-239, from its NS5A HCV inhibitor program.
	On September 30, 2014 the Company entered into an amendment to its 2012 collaboration and license agreement with Novartis to return to the Company full rights to its NS5A inhibitor program, including EDP-239, and to transition the proof-of-concept study to the Company. The Company owes no future payments to Novartis in connection with this transfer except for any unused drug product or ingredients that the Company may choose to buy from Novartis.
	NIAID Contract
	On September 30, 2011, the Company entered into a contract with the National Institute of Allergy and Infectious Diseases (“NIAID”), a division of the National Institutes of Health (“NIH”), which contract provided for up to $42,700 in potential development funding to the Company over a five-year period. Under this contract NIAID has funded the preclinical and clinical development of a bridged bicyclic antibiotic to be used as a medical countermeasure against multiple biodefense Category A and B bacteria.
	The initial award under the initial term of the contract was $14,300. In August 2013, NIAID exercised the first two options under this agreement which obligated it to provide an additional $9,200 in funding to the Company for preclinical and early clinical development of its lead antibiotic candidate, bringing funding paid or committed to date by NIAID to approximately $23,500.
	The Company recognizes revenue under this agreement as development services are performed in accordance with the funding agreement. During the three months ended December 31, 2014 and 2013, $1,106 and $893 of revenue, respectively, was recognized under this agreement.
	In light of the Company’s strategic decision not to continue commercial development of the antibiotic candidate for non-biodefense indications, which it communicated to NIAID in December 2014, NIAID has confirmed that it is prepared to agree to amend the contract so it will be completed upon the Company’s delivery of the study report for the Phase 1 clinical study, which is expected in August 2015. NIAID may terminate performance of work under this contract if it determines that a termination is in the government’s interest, also referred to as a termination for convenience, or if the Company defaults in performing the contract.

Warrants_to_Purchase_Series_1_

Warrants to Purchase Series 1 Nonconvertible Preferred Stock and Series 1 Nonconvertible Preferred Stock	3 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Warrants to Purchase Series 1 Nonconvertible Preferred Stock and Series 1 Nonconvertible Preferred Stock	7	Warrants to Purchase Series 1 Nonconvertible Preferred Stock and Series 1 Nonconvertible Preferred Stock
	In October and November 2010, the Company issued warrants to purchase up to a total of 1,999,989 shares of Series 1 nonconvertible preferred stock, which expire on October 4, 2017. As these warrants are free-standing financial instruments that may require the Company to transfer assets upon exercise, these warrants are classified as liabilities. The Company is required to remeasure the fair value of these preferred stock warrants at each reporting date, with any adjustments recorded within the change in fair value of warrant liability included in other income (expense) in the consolidated statement of operations. On February 5, 2014, 225,408 warrants were exercised resulting in the net issuance of 223,153 shares of Series 1 nonconvertible preferred stock. As of December 31, 2014 and September 30, 2014, the total fair value of the Series 1 nonconvertible preferred stock was $183 and $202, respectively. As of December 31, 2014 and September 30, 2014, the total fair value of the Series 1 nonconvertible preferred stock warrants was $1,427 and $1,584, respectively.

StockBased_Awards

Stock-Based Awards	3 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Awards	8. Stock-Based Awards
	2012 Equity Incentive Plan
	The Company’s 2012 Equity Incentive Plan (the “2012 Plan”) permits the Company to sell or issue common stock or restricted common stock or to grant incentive stock options or nonqualified stock options for the purchase of common stock, restricted stock units, stock appreciation rights or other cash incentive awards, to employees, members of the board of directors and consultants of the Company. The number of shares of common stock that may be issued under the 2012 Plan is subject to increase by the number of shares forfeited under any options terminated and not exercised under the previous plan, known as the 1995 Equity Incentive Plan as well as by a number of additional shares on the first day of each fiscal year equal to the lowest amount among the following: (i) 3% of the Company’s outstanding shares of common stock as of that date, (ii) 2,088,167 shares of common stock, or (iii) a lower amount determined by the board of directors. On October 1, 2014, the number of shares of common stock that may be issued under the 2012 Plan was increased by 557,863. As of December 31, 2014, 663,477 shares remained available for future grant.
	In March 2013, the Company granted to certain executives 167,052 options that vest upon the achievement of certain performance-based targets. The grant date fair value of these options was $2,479. During the three months ended December 31, 2014 and 2013, the Company recorded no compensation expense related to these options as none of the performance-based targets became probable of being achieved during these periods.
	Employee Stock Purchase Plan
	Under the Employee Stock Purchase Plan (the “ESPP”), a total of 185,614 shares of common stock were reserved for issuance. As of December 31, 2014, the Company has not commenced any offering under the ESPP and no shares have been issued.
	Stock Option Valuation
	The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model. The Company lacks sufficient company-specific historical volatility information. Therefore, it estimates its expected stock volatility based on the historical volatility of a selected group of publicly traded peer companies and expects to continue to do so until such time as it has adequate historical data regarding the volatility of its own traded stock price. The expected term of the Company’s stock options has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. Expected dividend yield is based on the fact that the Company has never paid cash dividends and does not expect to pay any cash dividends in the foreseeable future. The relevant data used to determine the value of the stock option grants is as follows, presented on a weighted average basis:
		Three Months Ended December 31,
		2014			2013
	Risk-free interest rate		1.92	%		1.89	%
	Expected term (in years)		6.1			6.09
	Expected volatility		76	%		74	%
	Expected dividend yield		0	%		0	%
	The Company recognizes compensation expense for only the portion of awards that are expected to vest. In developing a forfeiture rate estimate, the Company has considered its historical experience to estimate pre-vesting forfeitures for service-based awards. The impact of a forfeiture rate adjustment will be recognized in full in the period of adjustment, and if the actual forfeiture rate is materially different from the Company’s estimate, the Company may be required to record adjustments to stock-based compensation expense in future periods.
	As required by the 2012 Plan, the exercise price for awards granted is not to be less than the fair value of common shares as estimated by the Company as of the date of grant. For the periods prior to the March 2013 IPO, the Company valued its common stock by taking into consideration its most recently available valuation of common shares performed by management and the board of directors as well as additional factors which may have changed since the date of the most recent contemporaneous valuation through the date of grant. For the periods after the IPO, the Company based fair value of its common stock on the quoted market price.
	The following table summarizes stock option activity during the three months ended December 31, 2014:
		Shares			Weighted			Weighted		Aggregate
		Issuable			Average			Average		Intrinsic
		Under			Exercise			Remaining		Value
		Options			Price			Contractual
								Term
								(in years)
	Outstanding as of September 30, 2014		1,389,437		$	15.39			7.2	$	33,573
	Granted		311,055			43.75
	Exercised		(18,655	)		5.1
	Expired		(3,726	)		21.38
	Outstanding as of December 31, 2014		1,678,111		$	20.75			7.6	$	50,509
	Options vested and expected to vest as of December 31, 2014		1,494,527		$	21.32			7.4	$	44,140
	Options exercisable as of December 31, 2014		744,142		$	8.24			5.6	$	31,631
	The Company recorded stock-based compensation expense for the three months ended December 31, 2014 and 2013 in the following expense categories:
		Three Months Ended
		December 31,
		2014			2013
	Research and development	$	242		$	138
	General and administrative		786			221
		$	1,028		$	359
	As of December 31, 2014, the Company had an aggregate of $16,554 of unrecognized stock-based compensation cost, which is expected to be recognized over a weighted average period of 2.8 years.

Net_Income_Loss_Per_Share

Net Income (Loss) Per Share	3 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	9	Net Income (Loss) Per Share
	Basic and diluted net income (loss) per share attributable to common stockholders was calculated as follows for the three months ended December 31, 2014 and 2013:
			Three Months Ended
			December 31,
			2014		2013
	Basic net income (loss) per share:
	Numerator:
	Net income (loss)		$	42,009	$	(5,370	)
	Denominator:
	Weighted average common shares outstanding—basic			18,603,067		17,949,472
	Net income (loss) per share—basic		$	2.26	$	(0.30	)
	Diluted net income (loss) per share:
	Numerator:
	Net income (loss)		$	42,009	$	(5,370	)
	Denominator:
	Weighted average common shares outstanding—basic			18,603,067		17,949,472
	Dilutive effect of common stock equivalents			680,156		—
	Weighted average common shares outstanding—diluted			19,283,223		17,949,472
	Net income (loss) per share—diluted		$	2.18	$	(0.30	)
	Stock options for the purchase of 288,490 weighted average shares were excluded from the computation of diluted net income per share attributable to common stockholders for the three months ended December 31, 2014 because those options had an anti-dilutive impact due to the assumed proceeds per share using the treasury stock method being greater than the average fair value of the Company’s common shares for that period.
	Stock options for the purchase of 1,661,765 weighted average shares were excluded from the computation of diluted net loss per share attributable to common stockholders for the three months ended December 31, 2013 because those options had an anti-dilutive impact due to the net loss attributable to common stockholders.

Income_Taxes

Income Taxes	3 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	10	Income Taxes
	For the three months ended December 31, 2014 and December 31, 2013, the Company recorded an income tax provision of $28,502 and $0, respectively, representing an effective tax rate of 40.4% and 0.0%, respectively. The income tax provision for the three months ended December 31, 2014 was primarily attributable to the tax provision on the earnings of the Company’s domestic operations. During the three months ended December 31, 2014, the gross deferred tax assets decreased by $9,568 as a result of their utilization due to income before income taxes generated during the period.
	No provision for income tax was recorded for the three months ended December 31, 2013, as the Company maintained a valuation allowance against its deferred tax assets. The valuation allowance was reversed during the three months ended June 30, 2014.
	The Company files tax returns as prescribed by the tax laws of the jurisdictions in which it operates. In the normal course of business, the Company is subject to examination by federal and state jurisdictions, where applicable. There are currently no pending income tax examinations. The Company’s tax years are still open under statute from 2007 to the present. Earlier years may be examined to the extent that tax credit or net operating loss carryforwards are used in future periods.
	The Company had no unrecognized tax benefits as of December 31, 2014 or September 30, 2014. Unrecognized tax benefits represent tax positions for which reserves have been established. The Company’s policy is to record interest and penalties related to uncertain tax positions as part of its income tax provision.

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	11	Commitments and Contingencies
	Leases
	The Company has an office and laboratory lease that expires in September 2018. Payment escalation as specified in the lease agreement is accrued such that rent expense is recognized on a straight-line basis over the term of occupancy. The Company recorded rent expense of $237 for the three months ended December 31, 2014 and 2013.
	In connection with the lease, the Company has outstanding a $436 letter of credit, collateralized by a money market account. As of December 31, 2014 and September 30, 2014, the Company classified $436 related to the letter of credit as restricted cash.
	Intellectual Property Licenses
	The Company has a non-exclusive intellectual property license agreement with a third party, under which the Company is required to pay $200 in fiscal 2015 and (1) annual maintenance fees of $105 for each year that the agreement remains in effect, commencing on the first anniversary of the agreement, in order to maintain the right to use the license, and (2) a one-time fee of $50 in each circumstance in which the Company provides the licensed intellectual property to one of its collaborators with the prior consent of the licensor.
	The Company also has a non-exclusive license with respect to patents it uses in its HCV research. Under the license, the Company is obligated to pay milestones totaling up to $5,000, plus low single digit royalties, for the development and regulatory approval of each HCV product outside of the Company’s collaboration with AbbVie and any other collaboration it may enter into in the future with a partner that has already licensed these patents.
	Litigation and Contingencies Related to Use of Intellectual Property
	From time to time, the Company may become subject to legal proceedings, claims and litigation arising in the ordinary course of business. The Company currently is not a party to any threatened or pending litigation. However, third parties might allege that the Company or its collaborators are infringing their patent rights or that the Company is otherwise violating their intellectual property rights. Such third parties may resort to litigation against the Company or its collaborators, which the Company has agreed to indemnify. With respect to some of these patents, the Company expects that it will be required to obtain licenses and could be required to pay license fees or royalties, or both. These licenses may not be available on acceptable terms, or at all. A costly license, or inability to obtain a necessary license, could have a material adverse effect on the Company’s financial condition, results of operations or cash flows. The Company accrues contingent liabilities when it is probable that future expenditures will be made and such expenditures can be reasonably estimated.
	Indemnification Agreements
	In the ordinary course of business, the Company may provide indemnifications of varying scope and terms to customers, vendors, lessors, business partners, and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements, from services to be provided by the Company, or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with members of its board of directors and its executive officers that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnifications. In addition, the Company maintains officers and directors insurance coverage. The Company does not believe that the outcome of any claims under indemnification arrangements will have a material effect on its financial position, results of operations or cash flows, and it has not accrued any liabilities related to such obligations in its financial statements as of December 31, 2014.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates
	The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the consolidated financial statements, and the reported amounts of revenues and expenses during the reporting period. Significant estimates and assumptions reflected in these consolidated financial statements include, but are not limited to, valuation of warrants, Series 1 nonconvertible preferred stock and stock-based awards; the useful lives of property and equipment; and the accounting for income taxes, including uncertain tax positions. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from the Company’s estimates.
Revenue Recognition	Revenue Recognition
	The Company’s revenue is generated primarily through collaborative research and license agreements. The terms of these agreements contain multiple deliverables, which may include (i) licenses, (ii) research and development activities, and (iii) participation in joint research and development steering committees. The terms of these agreements may include nonrefundable upfront license fees, payments for research and development activities, payments based upon the achievement of certain milestones, and royalty payments based on product sales derived from the collaboration. In all instances, revenue is recognized only when the price is fixed or determinable, persuasive evidence of an arrangement exists, delivery has occurred or the services have been rendered, collectibility of the resulting receivable is reasonably assured, and the Company has fulfilled its performance obligations under the contract.
	For agreements entered into prior to October 1, 2011, the Company evaluated license agreements with multiple deliverables to determine if the deliverable elements could be recognized separately by considering (i) if the delivered elements (typically the license) had standalone value to the customer, (ii) if the fair value of any undelivered elements (typically the research and development services and the steering committee activities) could be determined based on vendor-specific objective evidence (“VSOE”) or vendor objective evidence (“VOE”), and (iii) if the arrangement included a general right of return relative to the delivered item, the delivery or performance of the undelivered item was considered probable and substantially within the control of the Company. VSOE of fair value was based on the consistent price of a deliverable when the Company regularly sold it on a standalone basis. Alternatively, VOE was based upon third-party objective evidence of fair value. If the delivered elements had value on a standalone basis and the fair value of the undelivered elements could be determined based on VSOE or VOE, revenues of such elements were then accounted for separately as delivered with arrangement consideration allocated to the delivered elements based on the residual value method. If either (i) the delivered elements were considered to not have standalone value or (ii) VSOE or VOE of fair value for any of the undelivered elements could not be determined, the arrangement was accounted for as a single unit of accounting and all payments received were recognized as revenue over the estimated period of performance of the entire arrangement.
	On October 1, 2011, the Company adopted Accounting Standards Update (“ASU”) No. 2009-13, Multiple-Deliverable Revenue Arrangements (“ASU 2009-13”). This guidance, which applies to multiple-element arrangements entered into or materially modified on or after October 1, 2011, amends the criteria for separating and allocating consideration in a multiple-element arrangement by modifying the fair value requirements for revenue recognition and eliminating the use of the residual value method. The selling prices of deliverables under the arrangement may be derived using third-party evidence (“TPE”) or a best estimate of selling price (“BESP”), if VSOE is not available. The objective of BESP is to determine the price at which the Company would transact a sale if the element within the license agreement was sold on a standalone basis. Establishing BESP involves management’s judgment and considers multiple factors, including market conditions and company-specific factors including those factors contemplated in negotiating the agreements as well as internally developed models that include assumptions related to market opportunity, discounted cash flows, estimated development costs, probability of success, and the time needed to commercialize a product candidate pursuant to the license. In validating the Company’s BESP, the Company considers whether changes in key assumptions used to determine the BESP will have a significant effect on the allocation of the arrangement consideration between the multiple deliverables. Deliverables under the arrangement are separate units of accounting if (i) the delivered item has value to the customer on a standalone basis, and (ii) if the arrangement includes a general right of return relative to the delivered item, delivery or performance of the undelivered item is considered probable and substantially within the control of the Company. The arrangement consideration that is fixed or determinable at the inception of the arrangement is allocated to the separate units of accounting based on their relative selling prices. The appropriate revenue recognition model is applied to each element, and revenue is accordingly recognized as each element is delivered. The Company may exercise significant judgment in determining whether a deliverable is a separate unit of accounting. The Company elected to adopt ASU 2009-13 prospectively as of October 1, 2011.
	In determining the separate units of accounting, the Company evaluates whether the license has standalone value to the collaborator based on consideration of the relevant facts and circumstances for each arrangement. Factors considered in this determination include the research and development capabilities of the collaborator and the availability of relevant research expertise in the marketplace. In addition, the Company considers whether or not (i) the collaborator can use the license for its intended purpose without the receipt of the remaining deliverables, (ii) the value of the license is dependent on the undelivered items, and (iii) the collaborator or other vendors can provide the undelivered items.
	Under a collaborative research and license agreement, a steering committee is typically responsible for overseeing the general working relationships, determining the protocols to be followed in the research and development performed, and evaluating the results from the continued development of the product in order to determine the clinical studies to be performed. The Company evaluates whether its participation in joint research and development steering committees is a substantive obligation or whether the services are considered inconsequential or perfunctory. The Company’s participation on a steering committee is considered “participatory” and therefore accounted for as a separate element when the collaborator requires the participation of the Company to ensure all elements of an arrangement are maximized. Steering committee services that are considered participatory are combined with other research services or performance obligations required under an arrangement, if any, in determining the level of effort required in an arrangement and the period over which the Company expects to complete its aggregate performance obligations. Alternatively, the Company’s participation on a steering committee is considered “protective” and therefore not accounted for as a separate element in a case where the Company can exercise or control when to be involved at its own discretion. Factors the Company considers in determining if its participation in a joint steering committee is participating or protective include: (i) which party negotiated or requested the steering committee, (ii) how frequently the steering committee meets, (iii) whether or not there are any penalties or other recourse if the Company does not attend the steering committee meetings, (iv) which party has decision making authority on the steering committee, and (v) whether or not the collaborator has the requisite experience and expertise associated with the research and development of the licensed intellectual property.
	For all periods presented, whenever the Company determines that an element is delivered over a period of time, revenue is recognized using either a proportional performance model or a straight-line model over the period of performance, which is typically the research and development term. Full-time equivalents (“FTEs”) are typically used as the measure of performance. At each reporting period, the Company reassesses its cumulative measure of performance and makes appropriate adjustments, if necessary. The Company recognizes revenue using the proportional performance model whenever the Company can make reasonably reliable estimates of the level of effort required to complete its performance obligations under an arrangement. Revenue recognized under the proportional performance model at each reporting period is determined by multiplying the total expected payments under the contract (excluding royalties and payments contingent upon achievement of milestones) by the ratio of the level of effort incurred to date to the estimated total level of effort required to complete the performance obligations under the arrangement. Revenue is limited to the lesser of the cumulative amount of payments received or the cumulative amount of revenue earned, as determined using the proportional performance model as of each reporting period. Alternatively, if the Company cannot make reasonably reliable estimates of the level of effort required to complete its performance obligations under an arrangement, then revenue under the arrangement is recognized on a straight-line basis over the period expected to complete the Company’s performance obligations. If and when a contingent milestone payment is earned, the additional consideration to be received is allocated to the separate units of accounting in the arrangement based on their relative selling prices at the inception of the arrangement. Revenue is limited to the lesser of the cumulative amount of payments received or the cumulative amount of revenue earned, as determined on a straight-line basis as of the period end date. If the Company cannot reasonably estimate when its performance obligation period ends, then revenue is deferred until the Company can reasonably estimate when the performance obligation period ends.
	Royalty revenue is recognized based on contractual terms when reported sales are reliably measurable and collectibility is reasonably assured, provided that there are no performance obligations then remaining.
	During the three months ended December 31, 2014 and 2013 the Company also generated revenue from a government contract, under which the Company is reimbursed for certain allowable costs for the funded project. Revenue from the government contract is recognized when the related service is performed. The related costs incurred by the Company under the government contract are included in research and development expenses in the statements of operations.
	Amounts received prior to satisfying all revenue recognition criteria are recorded as deferred revenue in the accompanying consolidated balance sheets. Amounts not expected to be recognized as revenue within the next twelve months of the consolidated balance sheet date are classified as long-term deferred revenue.
	In the event that a collaborative research and license agreement is terminated and the Company then has no further performance obligations, the Company recognizes as revenue any amounts that had not previously been recorded as revenue but were classified as deferred revenue at the date of such termination.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements
	In May, 2014, the Financial Accounting Standards Board (the “FASB”) issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), which supersedes all existing revenue recognition requirements, including most industry-specific guidance. The new standard requires a company to recognize revenue when it transfers goods or services to customers in an amount that reflects the consideration that the company expects to receive for those goods or services. The new standard will be effective for us on October 1, 2017. The Company is currently evaluating the potential impact that Topic 606 may have on its financial position and results of operations.

Fair_Value_of_Financial_Assets1

Fair Value of Financial Assets and Liabilities (Tables)	3 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Financial Assets and Liabilities that were Subject to Fair Value Measurement on Recurring Basis	The following tables present information about the Company’s financial assets and liabilities that were subject to fair value measurement on a recurring basis as of December 31, 2014 and September 30, 2014 and indicate the fair value hierarchy of the valuation inputs utilized to determine such fair value:
		Fair Value Measurements as of December 31, 2014 Using:
		Level 1			Level 2			Level 3		Total
	Assets:
	Money market fund	$	27,046		$	—		$	—	$	27,046
	Commercial paper		—			5,000			—		5,000
	Corporate bonds		—			87,951			—		87,951
	U.S. Agency bonds		—			5,509			—		5,509
		$	27,046		$	98,460		$	—	$	125,506
	Liabilities:
	Warrant liability	$	—		$	—		$	1,427	$	1,427
	Series 1 nonconvertible preferred stock	$	—		$	—		$	183	$	183
		$	—		$	—		$	1,610	$	1,610
		Fair Value Measurements as of September 30, 2014 Using:
		Level 1			Level 2			Level 3		Total
	Assets:
	Money market fund	$	30,239		$	—		$	—	$	30,239
	Commercial paper		—			7,499			—		7,499
	Corporate bonds		—			88,056			—		88,056
	U.S. Agency bonds		—			5,513			—		5,513
		$	30,239		$	101,068		$	—	$	131,307
	Liabilities:
	Warrant liability	$	—		$	—		$	1,584	$	1,584
	Series 1 nonconvertible preferred stock	$	—		$	—		$	202	$	202
		$	—		$	—		$	1,786	$	1,786
Fair Value Measurements of the Company's Warrant Liability and Series 1 Nonconvertible Preferred Stock	The recurring Level 3 fair value measurements of the Company’s warrant liability and Series 1 nonconvertible preferred stock using probability-weighted discounted cash flow include the following significant unobservable inputs:
		Unobservable Input		Range
				(Weighted
				Average)
	Warrant liability and Series 1 nonconvertible preferred stock	Probabilities of payout		10% - 55%
		Periods in which payout is expected to occur		2016 – 2017
		Discount rate		4.25%
Rollforward of Aggregate Fair Values of Warrants	The following table provides a rollforward of the aggregate fair values of the Company’s warrants for the purchase of Series 1 nonconvertible preferred stock and the outstanding Series 1 nonconvertible preferred stock for which fair value is determined by Level 3 inputs:
		Warrant			Series 1
		liability			nonconvertible
					preferred
					stock
	Balance, September 30, 2014	$	1,584		$	202
	Decrease in fair value		(157	)		(19	)
	Balance, December 31, 2014	$	1,427		$	183

Marketable_Securities_Tables

Marketable Securities (Tables)	3 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Fair Value of Available-for-Sale Marketable Securities by Type of Security	As of December 31, 2014 and September 30, 2014, the fair value of available-for-sale marketable securities by type of security was as follows:
		December 31, 2014
		Amortized Cost		Gross Unrealized		Gross Unrealized			Fair Value
				Gains		Losses
	Corporate bonds	$	88,042	$	11	$	(102	)	$	87,951
	U.S. Agency bonds		5,510		—		(1	)		5,509
		$	93,552	$	11	$	(103	)	$	93,460
		September 30, 2014
		Amortized Cost		Gross Unrealized		Gross Unrealized			Fair Value
				Gains		Losses
	Commercial paper	$	7,499	$	—	$	—		$	7,499
	Corporate bonds		88,156		14		(114	)		88,056
	U.S. Agency bonds		5,513		—		—			5,513
		$	101,168	$	14	$	(114	)	$	101,068

Accrued_Expenses_and_Other_Lon1

Accrued Expenses and Other Long-Term Liabilities (Tables)	3 Months Ended
	Dec. 31, 2014
Payables and Accruals [Abstract]
Accrued Expenses (Current) and Other Long-Term Liabilities	Accrued expenses (current) and other long-term liabilities consisted of the following as of December 31, 2014 and September 30, 2014:
		December 31,		September 30,
		2014		2014
	Accrued expenses:
	Accrued payroll and related expenses	$	584	$	1,275
	Accrued preclinical and clinical expenses		568		493
	Accrued vendor manufacturing		412		116
	Accrued third-party license fees		299		240
	Accrued professional fees		228		436
	Accrued other		312		312
		$	2,403	$	2,872
	Other long-term liabilities:
	Accrued rent expense	$	153	$	153
	Asset retirement obligation		85		76
		$	238	$	229

StockBased_Awards_Tables

Stock-Based Awards (Tables)	3 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Data Used to Determine Value of Stock Option Grants, Presented on Weighted Average Basis	The relevant data used to determine the value of the stock option grants is as follows, presented on a weighted average basis:
		Three Months Ended December 31,
		2014			2013
	Risk-free interest rate		1.92	%		1.89	%
	Expected term (in years)		6.1			6.09
	Expected volatility		76	%		74	%
	Expected dividend yield		0	%		0	%
Stock Option Activity	The following table summarizes stock option activity during the three months ended December 31, 2014:
		Shares			Weighted			Weighted		Aggregate
		Issuable			Average			Average		Intrinsic
		Under			Exercise			Remaining		Value
		Options			Price			Contractual
								Term
								(in years)
	Outstanding as of September 30, 2014		1,389,437		$	15.39			7.2	$	33,573
	Granted		311,055			43.75
	Exercised		(18,655	)		5.1
	Expired		(3,726	)		21.38
	Outstanding as of December 31, 2014		1,678,111		$	20.75			7.6	$	50,509
	Options vested and expected to vest as of December 31, 2014		1,494,527		$	21.32			7.4	$	44,140
	Options exercisable as of December 31, 2014		744,142		$	8.24			5.6	$	31,631
Stock-Based Compensation Expense	The Company recorded stock-based compensation expense for the three months ended December 31, 2014 and 2013 in the following expense categories:
		Three Months Ended
		December 31,
		2014			2013
	Research and development	$	242		$	138
	General and administrative		786			221
		$	1,028		$	359

Net_Income_Loss_Per_Share_Tabl

Net Income (Loss) Per Share (Tables)	3 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Basic and Diluted Net Income (Loss) Per Share Attributable to Common Stockholders	Basic and diluted net income (loss) per share attributable to common stockholders was calculated as follows for the three months ended December 31, 2014 and 2013:
		Three Months Ended
		December 31,
		2014		2013
	Basic net income (loss) per share:
	Numerator:
	Net income (loss)	$	42,009	$	(5,370	)
	Denominator:
	Weighted average common shares outstanding—basic		18,603,067		17,949,472
	Net income (loss) per share—basic	$	2.26	$	(0.30	)
	Diluted net income (loss) per share:
	Numerator:
	Net income (loss)	$	42,009	$	(5,370	)
	Denominator:
	Weighted average common shares outstanding—basic		18,603,067		17,949,472
	Dilutive effect of common stock equivalents		680,156		—
	Weighted average common shares outstanding—diluted		19,283,223		17,949,472
	Net income (loss) per share—diluted	$	2.18	$	(0.30	)

Fair_Value_of_Financial_Assets2

Fair Value of Financial Assets and Liabilities - Financial Assets and Liabilities that were Subject to Fair Value Measurement on Recurring Basis (Detail) (USD $)	Dec. 31, 2014	Sep. 30, 2014
In Thousands, unless otherwise specified
Assets:
Available for sale securities, fair value	$93,460	$101,068
Assets, Fair Value Disclosure, Total	125,506	131,307
Liabilities:
Liabilities, Fair Value Disclosure, Total	1,610	1,786
Warrant Liability [Member]
Liabilities:
Warrant liability	1,427	1,584
Money Market Fund [Member]
Assets:
Available for sale securities, fair value	27,046	30,239
Commercial Paper [Member]
Assets:
Available for sale securities, fair value	5,000	7,499
Corporate Bonds [Member]
Assets:
Available for sale securities, fair value	87,951	88,056
U.S. Agency Bonds [Member]
Assets:
Available for sale securities, fair value	5,509	5,513
Series 1 Nonconvertible Preferred Stock [Member]
Liabilities:
Warrant liability	1,427	1,584
Series 1 nonconvertible preferred stock	183	202
Level 1 [Member]
Assets:
Assets, Fair Value Disclosure, Total	27,046	30,239
Level 1 [Member] | Money Market Fund [Member]
Assets:
Available for sale securities, fair value	27,046	30,239
Level 2 [Member]
Assets:
Assets, Fair Value Disclosure, Total	98,460	101,068
Level 2 [Member] | Commercial Paper [Member]
Assets:
Available for sale securities, fair value	5,000	7,499
Level 2 [Member] | Corporate Bonds [Member]
Assets:
Available for sale securities, fair value	87,951	88,056
Level 2 [Member] | U.S. Agency Bonds [Member]
Assets:
Available for sale securities, fair value	5,509	5,513
Level 3 [Member]
Liabilities:
Liabilities, Fair Value Disclosure, Total	1,610	1,786
Level 3 [Member] | Warrant Liability [Member]
Liabilities:
Warrant liability	1,427	1,584
Level 3 [Member] | Series 1 Nonconvertible Preferred Stock [Member]
Liabilities:
Series 1 nonconvertible preferred stock	$183	$202

Fair_Value_of_Financial_Assets3

Fair Value of Financial Assets and Liabilities - Additional Information (Detail) (USD $)	3 Months Ended		12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers between Level 1, Level 2 and Level 3	$0	$0
Series 1 nonconvertible preferred stock issued	1,427,000		1,584,000
Series 1 Nonconvertible Preferred Stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of Series 1 nonconvertible preferred stock	$183,000		$202,000

Fair_Value_of_Financial_Assets4

Fair Value of Financial Assets and Liabilities - Fair Value Measurements of the Company's Warrant Liability and Series 1 Nonconvertible Preferred Stock (Detail) (Warrant Liability [Member], Series 1 Nonconvertible Preferred Stock [Member])	3 Months Ended
	Dec. 31, 2014
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Periods in which payout is expected to occur, beginning	2016
Periods in which payout is expected to occur, ending	2017
Discount rate	4.25%
Minimum [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Probabilities of payout	10.00%
Maximum [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Probabilities of payout	55.00%

Fair_Value_of_Financial_Assets5

Fair Value of Financial Assets and Liabilities - Rollforward of Aggregate Fair Values of Warrants (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Series 1 Nonconvertible Preferred Stock [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$202
Decrease in fair value	-19
Ending Balance	183
Warrant Liability [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	1,584
Decrease in fair value	-157
Ending Balance	$1,427

Marketable_Securities_Fair_Val

Marketable Securities - Fair Value of Available-for-Sale Marketable Securities by Type of Security (Detail) (USD $)	Dec. 31, 2014	Sep. 30, 2014
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$93,552	$101,168
Gross Unrealized Gains	11	14
Gross Unrealized Losses	-103	-114
Fair Value	93,460	101,068
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		7,499
Fair Value	5,000	7,499
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	88,042	88,156
Gross Unrealized Gains	11	14
Gross Unrealized Losses	-102	-114
Fair Value	87,951	88,056
U.S. Agency Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,510	5,513
Gross Unrealized Losses	-1
Fair Value	$5,509	$5,513

Marketable_Securities_Addition

Marketable Securities - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014
Schedule of Available-for-sale Securities [Line Items]
Marketable securities maturing in greater than one year, aggregate fair value	23,568	41,003
Short Term Marketable Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Maturity period of the marketable securities	Within one year	Within one year
Corporate Bond Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Maturity period of the marketable securities	Within three years	Within three years
U.S. Agency Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Maturity period of the marketable securities		Within three years

Accrued_Expenses_and_Other_Lon2

Accrued Expenses and Other Long-Term Liabilities - Accrued Expenses (Current) and Other Long-Term Liabilities (Detail) (USD $)	Dec. 31, 2014	Sep. 30, 2014
In Thousands, unless otherwise specified
Accrued expenses:
Accrued payroll and related expenses	$584	$1,275
Accrued preclinical and clinical expenses	568	493
Accrued vendor manufacturing	412	116
Accrued third-party license fees	299	240
Accrued professional fees	228	436
Accrued other	312	312
Accrued expenses	2,403	2,872
Other long-term liabilities:
Accrued rent expense	153	153
Asset retirement obligation	85	76
Other long-term liabilities	$238	$229

Collaboration_Agreements_Addit

Collaboration Agreements - Additional Information (Detail) (USD $)	3 Months Ended		0 Months Ended	12 Months Ended	1 Months Ended	0 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2011	Sep. 30, 2011	Sep. 30, 2014	Mar. 31, 2015	Sep. 30, 2014	Aug. 31, 2013
National Institutes of Health, National Institute of Allergy and Infectious Diseases [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration agreement date	30-Sep-11
Funding related to research and development	$23,500,000							$9,200,000
Revenue from grants	1,106,000	893,000
National Institutes of Health, National Institute of Allergy and Infectious Diseases [Member] | Initial [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Awarded contract for development, amount			14,300,000
National Institutes of Health, National Institute of Allergy and Infectious Diseases [Member] | Maximum [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Awarded contract for development, amount				42,700,000
Awarded contract for development, contract period				5 years
AbbVie [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration agreement date	27-Nov-06
Collaboration agreement tiered royalty description	From the low double digits up to twenty percent, or on a blended basis from the low double digits up to the high teens, on net sales
Upfront license payments, preferred stock sale proceeds, research funding, and milestone payments					160,000,000
Milestone revenue recognized	75,000,000
AbbVie [Member] | Milestone Payments [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Expected proceed from milestone payment	80,000,000
AbbVie [Member] | Milestone Payments [Member] | Additional Funding Agreement Terms [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Expected proceed from milestone payment	80,000,000
AbbVie [Member] | Subsequent Event [Member] | Milestone Payments [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Expected proceed from milestone payment						50,000,000
AbbVie [Member] | Paritaprevir 3-DAA Regimen [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Percentage of net sales to be allocated	30.00%
AbbVie [Member] | Paritaprevir 2-DAA Regimen [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Percentage of net sales to be allocated	45.00%
AbbVie [Member] | Abt 493 2-DAA Regimen [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Percentage of net sales to be allocated	50.00%
AbbVie [Member] | Abt 493 3-DAA Regimen [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Percentage of net sales to be allocated	33.33%
Novartis [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Future milestone payments							$0

Warrants_to_Purchase_Series_1_1

Warrants to Purchase Series 1 Nonconvertible Preferred Stock and Series 1 Nonconvertible Preferred Stock - Additional Information (Detail) (Series 1 Nonconvertible Preferred Stock [Member], USD $)	0 Months Ended	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Feb. 05, 2014	Dec. 31, 2014	Sep. 30, 2014	Nov. 30, 2010
Series 1 Nonconvertible Preferred Stock [Member]
Changes In Equity And Comprehensive Income Line Items [Line Items]
Number of shares issuable upon exercise of the warrants				1,999,989
Warrant expiration date		4-Oct-17
Warrant exercised	225,408
Warrants issuance	223,153
Fair value of the Series 1 nonconvertible preferred stock		$183	$202
Fair value of warrants		$1,427	$1,584

StockBased_Awards_Additional_I

Stock-Based Awards - Additional Information (Detail) (USD $)	0 Months Ended	3 Months Ended	1 Months Ended	3 Months Ended
	Dec. 31, 2014	Dec. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Sep. 30, 2013	Oct. 01, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted to executives		311,055
Common stock reserved					185,614
Shares issued under the ESPP	0
Aggregate of unrecognized stock-based compensation cost	$16,554,000	$16,554,000
Weighted average recognition period		2 years 9 months 18 days
2012 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock shares authorized						557,863
Percentage of potential common stock shares to be issued		3.00%
Potential number of common stock shares to be issued		2,088,167
Shares available for future grant	663,477	663,477
2012 Equity Incentive Plan [Member] | Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted to executives			167,052
Fair value of options at the grant date			2,479,000
Stock based compensation, expenses		$0		$0

StockBased_Awards_Data_Used_to

Stock-Based Awards - Data Used to Determine Value of Stock Option Grants, Presented on Weighted Average Basis (Detail)	3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Risk-free interest rate	1.92%	1.89%
Expected term (in years)	6 years 1 month 6 days	6 years 1 month 2 days
Expected volatility	76.00%	74.00%
Expected dividend yield	0.00%	0.00%

StockBased_Awards_Stock_Option

Stock-Based Awards - Stock Option Activity (Detail) (USD $)	0 Months Ended	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2014
Shares Issuable Under Options
Outstanding as of beginning of period	1,389,437	1,389,437
Granted		311,055
Exercised		-18,655
Expired		-3,726
Outstanding as of end of period		1,678,111
Options vested and expected to vest as of end of period		1,494,527
Options exercisable as of end of period		744,142
Weighted Average Exercise Price
Outstanding as of beginning of period	$15.39	$15.39
Granted		$43.75
Exercised		$5.10
Expired		$21.38
Outstanding as of ending balance		$20.75
Options vested and expected to vest as of end of period		$21.32
Options exercisable as of end of period		$8.24
Weighted Average Remaining Contractual Term (In years)
Outstanding as of end of period	7 years 2 months 12 days	7 years 7 months 6 days
Options vested and expected to vest as of end period		7 years 4 months 24 days
Options exercisable as of end of period		5 years 7 months 6 days
Aggregate Intrinsic Value
Outstanding as of beginning of period	$33,573	$33,573
Outstanding as of end of period		50,509
Options vested and expected to vest as of end of period		44,140
Options exercisable as of end of period		$31,631

StockBased_Awards_StockBased_C

Stock-Based Awards - Stock-Based Compensation Expense (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$1,028	$359
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	242	138
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$786	$221

Net_Income_Loss_Per_Share_Basi

Net Income (Loss) Per Share - Basic and Diluted Net Income (Loss) Per Share Attributable to Common Stockholders (Detail) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Basic net income (loss) per share:
Net income (loss)	$42,009	($5,370)
Weighted average common shares outstanding-basic	18,603,067	17,949,472
Net income (loss) per share-basic	$2.26	($0.30)
Diluted net income (loss) per share:
Net income (loss)	$42,009	($5,370)
Weighted average common shares outstanding-basic	18,603,067	17,949,472
Dilutive effect of common stock equivalents	680,156
Weighted average common shares outstanding-diluted	19,283,223	17,949,472
Net income (loss) per share-diluted	$2.18	($0.30)

Net_Income_Loss_Per_Share_Addi

Net Income (Loss) Per Share - Additional Information (Detail) (Stock Option [Member])	3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Stock Option [Member]
Dilutive Securities Included And Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares excluded from the computation of diluted net income per share	288,490	1,661,765

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2014
Income Tax Disclosure [Abstract]
Income tax provision	$28,502,000	$0
Effective income tax rate	40.40%	0.00%
Gross deferred tax assets related to net operating loss carry forwards, Decrease	9,568,000
Unrecognized tax benefits	$0		$0

Commitments_and_Contingencies_

Commitments and Contingencies - Additional Information (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2014
Commitments And Contingencies [Line Items]
Rent expense	$237	$237
Office lease expiration period	Sep-18
Outstanding letter of credit	436
Restricted cash	436		436
Maintenance fees	105
One-time fee	50
Company's obligation to pay	5,000
Fiscal Year 2015 [Member]
Commitments And Contingencies [Line Items]
License expense	$200